Orion KL in Band 1
Science Target Overview
Orion KL is the well-known, closest massive star-forming region at a distance of 400 pc in our Galaxy. It has several strong millimeter sources, and is also famous for its rich chemistry. Several line surveys have been conducted toward Orion KL in various frequency bands, including single-dish observations covering the entire ALMA Band 1 frequency range at high spectral resolutions. Numerous lines have been detected at high signal-to-noise ratio in the ALMA Band 1 frequency range. Thus, it is an excellent target to demonstrate and verify the ALMA Band 1 spectral scan capability by comparison with these previous observations.
ALMA Data Overview
Observations with the spectral scan mode covering the frequency range from 35.1 to 49.63 GHz at a spectral resolution of 244.172 kHz were carried out with 4 different observations from 2024 April 26 to April 28. The PWV was 2-3 mm. 36 to 41 antennas were used. A few antennas were heavily flagged during calibration. Total on-source time for the target source was about 129 min. The baseline lengths range from 15 to 500 m. The calibration was performed using the ALMA Pipeline in a standard manner. No further self calibration was performed. The data is affected by bandpass ripples with an amplitude of about 1%. The identification of continuum channels for continuum subtraction and imaging was done manually. The reference continuum and line images were generated with the Pipeline. Additional manual continuum imaging was performed. The continuum emission is clearly detected, and the continuum image is dynamic range limited due to the presence of the bright extended emission. There are more than 100 lines detected at high signal-to-noise ratio in the line images.
Using the data for publication
The following statement should be included in the acknowledgement of papers using the dataset listed above:
“This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00022.SV. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSTC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ."
Obtaining the Data
The data products are contained in the following directory:
The above directory contains README, uncalibrated data, calibrated data, data reduction and imaging scripts, and reference images.